1. Technical Field
This disclosure relates generally to rotational equipment and, more particularly, to a seal assembly for arranging between a stator and a rotor of, for example, a turbine engine.
2. Background Information
A seal assembly is typically used in rotational equipment to provide a seal between regions of high and low fluid pressure and/or temperature. A seal assembly may be used, for example, to provide a gas and/or liquid seal between a stator and a rotor of a turbine engine, a pump, a compressor, a turbine of a hydro-electric or wind generator, as well as various other types of rotational equipment.
FIG. 1 illustrates a sectional illustration of a seal assembly 20 for sealing a gap between a turbine engine shaft 22 and a strut 24 connected to a turbine engine case. The seal assembly 20 includes an annular seal housing 26, an annular shaft sleeve 28 and a pair of annular carbon seal elements 30. The seal housing 26 includes a housing sleeve 27 and a housing insert 29, which is connected to the housing sleeve 27 with a retaining ring 31. The housing sleeve 27 is connected to the strut 24. The shaft sleeve 28 is mounted onto the shaft 22. The seal elements 30 are arranged within and axially contact the seal housing 26. The seal elements 30 radially contact the shaft sleeve 28.
The shaft sleeve 28 rotates with the shaft 22 during turbine engine operation. Under certain conditions, shaft runout may cause the shaft sleeve 28 and, thus, the seal elements 30 to radially shift relative to the seal housing 26. Referring to FIG. 2, the radial shifting between each seal element 30 and the seal housing 26 may create an arcuate or annular step 32 in an end 34 of the seal element 30. Referring now to FIG. 3, this step 32 may fracture during turbine engine operation and increase fluid leakage between the now fractured seal element 30 and the shaft sleeve 28 by providing, for example, a direct leakage passage through axial channels 36.
There is a need in the art for an improved seal assembly.